HPMC-Salicylate Conjugates as Macromolecular Prodrugs: Design, Characterization, and Nano-Rods Formation

Abstract

By the development of prodrugs, reduction in amount and frequency of dose can easily be achieved by more targeted drug delivery benefits of prodrugs, which indi rectly increases the patient compliance.1,2 In these days, fabrication of macromolecular prodrugs of non steroidal anti-inflammatory drugs (NSAIDs) by the covalent attachment of the drugs with biopolymers as an ester moiety is getting greater attention. In general, such ester conjugates of NSAIDs can easily be hydro lyzed at basic medium of colon in particular. Such link ages cannot be affected much by acidic hydrolysis in stomach. Hence, by this conversion of NSAIDs as an ester moiety onto glycopolymers, stomach can easily be kept secure by the harmful effects of the NSAIDs. In directly, by this way, colon specific drug delivery can easily be achievedPolysaccharides (glycopolymers) are entering into colon targeted drug delivery with high potential. 3, 4 Glycopolymers ‘‘the most promising macromolecular carriers’’made possible to deliver a wide variety of drugs, eg, peptides, proteins, nucleic acid, NSAIDs, anticancer drugs, and sensitive drugs to acidic environment directly to colon. 5–7 Use of glycopolymers are advantageous because these polymers target the site of action, increase the intensity and/or prolong pharmacologic action and/or reduce toxicity of small molecule drugs, proteins, or enzymes, and so forth. A significant number of publications have been reported about the macromolecular prodrugs fabrication of NSAIDs with polysaccharides and other polymers in which useful results were obtained. 8–11 However, there is no literature found for the use of cellulose ethers as drug career by making its ester derivatives. Cellulose ethers are of great research interest in the areas of biomedical and pharmaceutical sciences, for example, as carriers for drug targeting, vaccine bullets, sustained release of drug and material for disintegration of matrix tablets. On the other hand widely used cellulose ether, HPMC is semisynthetic, nonionic,